TABLE 3.

Determination of the optimal dilution of tested pig sera for cELISA

Serum no.	Serum type	1:80	1:40	1:20	1:10	1:5
1	Positive	0.773	0.501	0.476	0.445	0.413
	Negative	1.022	0.992	1.073	1.046	0.977
	P/N	0.756	0.505	0.444	0.425 a	0.423
2	Positive	0.505	0.374	0.217	0.181	0.167
	Negative	1.057	1.07	1.058	1.006	0.945
	P/N	0.478	0.35	0.205	0.180	0.177
3	Positive	0.334	0.276	0.217	0.156	0.142
	Negative	1.100	1.032	0.973	1.065	1.013
	P/N	0.304	0.267	0.223	0.146	0.14

^aThree positive and negative swine sera were separately used for cELISA detection. The dilutions of sera were 1:5, 1:10, 1:20, 1:40, and 1:80. The best dilution was selected when the OD₄₅₀ value of positive-to-negative (P/N) sera was smallest.